Mouthpiece for a spirometer device



FIG. 1 is a perspectiive view of a mouthpiece for a spirometer device showing my new design;

FIG. 2 is a side elevated view of the mouthpiece depicted in FIG. 1;

FIG. 3 is a end view of the mouthpiece of FIG. 1; and

FIG. 4 is a view of the opposite end thereof. 

The ornamental design for a mouthpiece for a spirometer device, substantially as shown and described. 